(SALEM) - A juvenile male has been arrested after police say he hit a fellow Salem High School student then drove on to school.

Stephanie Taylor Ferriell of the Leader -Democrat reports the juvenile is being held in the Jackson County Youth Detention Center on preliminary charges of leaving the scene of an accident and criminal recklessness with a vehicle.

He is not being identified at this time because he is a juvenile.

The victim, Logan Harding, 15, remains in critical condition at University of Louisville Hospital where he was flown Friday morning.

Detective Scott Ratts of the Salem City Police said Harding suffered chest and spleen injuries and was still undergoing evaluation Friday afternoon. Ratts credited the youth's backpack for saving him from very serious injury, possibly even death.

"He had his backpack on with books in it and that absorbed a lot of the impact," he said.

Harding was struck from behind. The impact was so great it knocked him out of his shoes.

It was a pair of shoes lying in the roadway that attracted the attention of the Good Samaritan who stopped to investigate. "She saw those shoes as she was on Shelby Street on her way to work at The Crossing," said Ratts. The woman told him it just didn't look right, so she stopped to investigate.

She discovered Harding lying on the side of Houston Street, near the Shelby Street intersection. Ratts said the teen had been lying there long enough to have dew on him.

Police, including lead investigator Officer Ronnie Mays, found automobile parts at the scene. One piece had a number on it, said Ratts. Officers took that part to Gilstrap Motors where they learned it came from a Ford pickup manufactured between 1992 and 1996.

They found the truck they say hit Harding parked in the Salem High School parking lot. The truck was made in 1996.